This invention relates to a number of chemically bonded phosphate ceramic (CBPC) formulations for specific oil field and geothermal well applications. Specific formulations are given for sealing shallow wells, i.e., down to about 10,000 feet, deep wells, those deeper that 10,000 feet, down-hole sealants for use off-shore where the availability of fresh water is limited and salt water is substituted. Also disclosed are formulations for light and heavy weight cements. Other formulations disclosed include a sealant based on aluminum phosphate for application in wells, including geothermal wells, which have temperatures greater that 300° F. and another ceramic based on calcium phosphate which may be used to prepare value-added products using drilling wastes.
In earlier inventions, Argonne National Laboratory (ANL) disclosed several chemically bonded phosphate ceramic (CBPC) binders, and Ceramicrete® formulation (CBPC formed by blend of MgO and KH2PO4 reacted with water) in particular, for applications in radioactive and hazardous waste management, structural materials, and also dental applications. Most of these applications are based on the fact that these rapid-setting phosphate ceramics exhibit superior properties compared to conventional cements. This observation also led the inventors to develop formulations of these materials for oil field applications, specifically, the invented formulations to deep and shallow wells and to lower and higher temperatures and pressures.
Additionally, the inventors have developed novel formulations, one based on aluminum phosphate and the other based on calcium phosphate, the former for use in geothermal wells and the latter for developing value-added products using drilling wastes.